Breathing appliance



Dec. 11, 1934. R H mm 1,984,119

BREATHING APPLIANCE Filed Dec. '22, 1931 3 Sheets-Sheet l Q, J W

Dec. 11, 1934. R H, DAVIS BREATHING APPLIANCE Filed Dec. 22, 1951 3Sheets-Sheet 2 wa /v03;

Dec. 11, 1934. R H, v s 1,984,119

BREATHING APPLIANCE Filed Dec. 22, 1951 3 Sheets-Sheet 3 l I JZ I 'imiiiPatented Dec. 11, 1934 UNITED STA -Es BREATHING APPLIANCE Robert HenryDavis, London, England Application December 22, 1931, Serial No. 582,624

g In Great-Britain October 15, 1931 3 Claims.

This invention is for improvements in or relating to breathingappliances adapted more especially for submarine use, of theself-contained type comprising a breathing bag in the form of aninflatable envelope of rubber or the like, a mouthpiece preferablyhaving means whereby it may be attached to the head of the personwearing the appliance, a breathing tube connecting the mouthpiece andbreathing bag, means for absorbing carbon dioxide from the exhaled airand means for admitting a charge of oxygen to the interior of thebreathing bag, for example, an oxygen cylinder forming a part of theappliance and provided with a valve controlled connection With thebreathing bag.

It is a difliculty with appliances of this type,

that the wearer, when he reaches the surface of the water, may be in anunconscious condition or too unwell to close the shut-off valve of thebreathing bag (usually provided in the mouthpiece of the appliance) andthereby convert this bag into a buoyancy chamber in the usual way (thewearer thereafter breathing from the open air instead of through themouthpiece) and if not rescued in a short time, may exhaust his supplyof air and oxygen in the breathing bag,

with the result that this bag may become so deflated as to be ofinsufficient buoyancy to keep the wearer afloat. Or, should the wearerbe unconscious or dead when he reaches the surface the mouthpiece maybecome dislodged from his mouth and exposed to the sea, whereupon thebreathing bag will simply flood, with complete loss of buoyancy to theappliance. In any of these contingencies, as will be appreciated, theperson wearing the appliance will sink, without leaving any trace of hiswhereabouts, and this is regarded as a distinct drawback with existingforms of appliance of the type referred to.

The object of thepresent invention is to provide a modification of saidexisting forms of the appliance whereby this difliculty may in a simpleand effective manner be met.

According to the present invention, a breathing appliance of the typereferred to comprises, in combination, an inflatable breathing bag, amouthpiece, a breathing tube connecting the mouthpiece and breathingbag, means for admitting a charge of respiratory gas to the breathingbag, means for absorbing carbon dioxide from the exhaled air, aninflatable buoyancy chamber additional to the breathing bag and integraltherewith, a passage leading from the breathing bag to the buoyancychamber and a non-return valve controlling said passage and permittingflow of gas from the breathing bag to the buoyancy chamber for theinflation of the latter.

As will be appreciated, the provision, as above,

of an additional buoyancy chamber provides in 5 a simple manner againstthe contingencies referred to by serving to keep the wearer afloat eventhough he should, as stated, have exhausted the whole of his air andoxygen supply and thus the breathing bag should have become deflated andhave lost its buoyancy, or, again, even if the breathing bag should havebecome flooded and for this reason have lost its buoyancy. 7

Moreover, with the additional buoyancy bag, the wearer of the appliancehas no need to conserve his oxygen supply to ensure that he hassufficient to keep him afloat when he reaches the surface; he can usethe whole of his oxygen for breathing purposes, relying on theadditional buoyancy bag to keep him afloat. 2

The invention will now be further described with reference to theaccompanying drawings which illustrate several embodiments by way ofexample, in which:

Figure 1 isa front elevation of a breathing appliance in accordance withthe invention;

Figure 2 is a vertical cross-section through the appliance taken on thesection line 2- 2 of Figure 1;

Figures 3 and 4 are a front elevation of and vertical cross-sectionthrough a modified construction in accordance with the invention, and

Figures 5 and 6 are similar views showing a further modifiedconstruction.

Like reference numerals indicate like parts in ,35

the various figures.

The appliance, as shown in Figures 1 and 2, comprises a breathing bag inthe form of a rubber envelope 10, communicating with a mouthpiece 11 byaflexibletubular connection 12.

Accommodated in a strap'fltting 13 at the bottom of the envelope is acylinder 14, of compressed oxygen, having a connection 15 to theenvelope 10. This connection is controlled by a valve 16, andterminates, within the envelope, in a nozzle fitting 17, adapted tocarry a small capsule 18 of compressed oxygen having a readily breakableneck 19 by which it is connected to the nozzle fitting 17.

Vulcanized on to the front face of the envelope 10 is an additionalbuoyancy chamber in accordance with the present invention, in the formof a collapsible envelope 20 of rubber. This envelope is arranged to beinflated from the breathing bag, the air entering the chamber by anonblowing through the inlet 21.

return Valve 26 in the wall of the breathing bag, which valve may be ofany convenient construction.

The envelope 20 may also be provided for its inflation with an inlet 21through which gas, for example, breath from the user of the appliance,may be forced directly into the envelope.

A non-return relief valve 22 is fitted in the wall of the envelope toprevent its over-inflation.

In place of the inflation inlet 21, or in addition thereto, the buoyancychamber may be arranged to be inflated in known manner by gas, forsexample, air, released from a small breakable capsule 23 containing thegas under pressure. This capsule is mounted upon theinner faceof a cap24 screwed into a socket 25 vulcanized into the Wall of the envelope.

The construction shown in Figures 3 and 4: is one in which two buoyancychambers'2'7, 28 are provided interconnected by a passage-way 29.

The=chambers are inflated as in the previous construction by air fromthe breathing bag, the air entering the passage-way 29 by a non-returnvalve 26 in the wall of the breathing bag.

Figures- .and 6 illustrate a further modification, in which the buoyancychamber is incorporated in the lower part of the breathing bag envelopeby the provision therein of a partition 30; IAs. in the previousconstructions, the buoy- .ancychamber is-inflated by air from thebreathingr-bag envelope, and for thispurpose a nonreturn valve26is'provided in the partition 30.

In. the two modified constructions illustrated respectively in Figures 3and 4 and Figures 5 and 6, thebuoyancy chamber, may, if desired, be

fitted, as'in the construction first described, with .a direct-inflationinlet 21 (shown in chain line), or with a breakable compressed gascapsule. 23

(also; shown in chain line), or with both.

As will be appreciated, the provision of a direct-inflation inlet 21 orabreakable compressed gas'capsule23, in addition to a non-return valve'.26"ir1':the wall of thebreathingbag envelope, en-

hances the utility of the appliance. Thus, for

instance, if circumstances permit, the wearer of the appliance. caninitially inflate the buoyancy chamber. by'iexhaling his breathinto theinlet 2.1,..and .this initial iinflati'on' through the inlet 21 willserve to reduce the consumption of oxygen .or-tair-fromihe;breathingrbagfor buoyancy purposes. Again, the same result may be achieved bybreakingthe gas capsule 23, in the event of circumstances 'notpermitting thewearer of the appliance to inflate-the buoyancy chamber by Moreover, ifthe non-return valve 26 should become inoperative .for'any reason, sothat air is prevented from passing itfromthetbreathingbag to thebuoyancy chamber, the wearer'can use either of his alternativeinflationt means, according to desire oras circumstances permit.

It is to be understood, however, that although, generally speaking, forexample, for the reason just referred to, it is desirable to provide, inaddition to the non-return valve 26, for the inflation of the buoyancychamber, a direct-inflation inlet (21) or/and a breakable gas capsule(23) these supplementary inflation means may, if desired, be omitted.

It will beobserved that the invention-.iscapable of considerablevariation in the precise form and position employed of the buoyancychamber, and in other structural details without departing from thescope and spirit of the invention.

What I- claim is:

1. A. self-contained breathing appliance tor submarine use, comprising,in combination, an inflatable breathing bag, a mouthpiece, abreathing'tubeconnecting the mouthpiece and breathing bag, means foradmitting a charge of respiratory gas to the breathing bag, means forabsorbing carbon dioxide from the exhaled air, an inflatable buoyancychamber additional to the breathing bag, a passage leading from thebreathing bag. to the buoyancy chamber and a nonreturnvalve controllingsaid passage and per- .mitting flow of gas from the breathing bag to thebuoyancy chamber for the inflation of the latter.

2. A self-contained breathing appliance. for submarine use, comprising,in combination, an inflatable envelope, a partition therein dividing theinterior of the envelope into two separate compartments, one of-whichcompartments constitutes-a breathing bag and the other a buoyancychamber additional thereto, a mouthpiece, a

breathing tube connecting the mouth iece and the breathing bag, meansfor admitting a charge of respiratory gas to the breathing bag; meansfor absorbing carbon dioxide from the exhaled air, a passage leadingfrom the breathing bag to the buoyancy chamber, and a non-return valvecontrolling said passage and permitting flow of gas from the breathingbag to the buoyancy chamberfor the inflation of the latter.

3. A; self-contained breathing appliance for submarine use, comprising,in combination, an inflatable breathing bag, a mouthpiece, abreathingtube connecting the mouthpiece and breathing bag, means for admitting acharge of respiratory gastothe' breathing bag, means for absorbingcarbon dioxide from the-exhaled air, an inflatable buoyancychamber'mounted upon the exterior of the breathing bag, a passageleading from the breathing bag to the buoyancy cham-- ber andanon-returnvalve controlling said passage andp'ermitting flow of gas from the bagto the chamberfor the inflation of the latter.

ROBERT HENRY" DAVIS.

